配网铁磁谐振过电压的非线性动力学分析及抑制措施的研究

Nonlinear Dynamic Analysis and Suppression Method of Ferroresonance Overvoltage in Distribution Network

配电网中电磁式电压互感器引起的铁磁谐振过电压出现频繁,严重影响电力系统的稳定运行,研究一种快速、有效的消谐措施意义重大。利用非线性动力学对配电网系统发生的铁磁谐振过电压进行仿真分析,得到随着系统对地电容变化的分岔图及相应的最大李雅普诺夫指数曲线图,分析该系统下各类谐振的变化情况。在此基础上,研究配电网中性点经ZnO非线性电阻接地方式对铁磁谐振过电压的抑制方式,并获取能够抑制各类谐振的非线性电阻的伏安特性。结果表明:中性点经ZnO非线性电阻接地方式能够使过电压幅值降低到正常情况,同时混沌谐振现象消失,说明中性点经适当的非线性电阻可以有效地抑制铁磁谐振过电压。

Ferroresonance overvohage caused by the potential transformer occurs frequently in distribution networks, which affects the stable operation of the power system seriously. Therefore, a reliable, stable and convenient way to eliminate the ferroresonance is urgently in need. In this paper, the magnetization curve of the potential transformer is obtained by calculating the test dates of JDZX9-10G, and different types of ferroresonance are analyzed by the space trajectory. On this basis, the ferroresonance overvoltage inhibiting with ZnO nonlinear resistance grounding mode is researched, and the acquisition of ZnO nonlinear resistance is described in detail. The method is verified by ATP-EMTP and the results show that the voltage amplitude of the neutral point through nonlinear resistance decreases to normal circumstances and the chaotic phenomena is eliminated, which means that the resonance elimination measure of neutral point through nonlinear resistance can well inhibit the ferroresonance overvohage.